Hemi with yellow crud in oil cap

[UKCatsfan]

I have an 04 Durango with the 5.7 Hemi and noticed yellow brud in the oil cap that apears to be baked on. It is only on half of the cap. I just changed back to Mobil 1 5w30 from GC. What could this be?

 

[Blue99]

If the valve cover has a 3-4" plastic extension tube that the oil cap screws into, the deposits are a result of condensation from crankcase vapors. The cooler surfaces of the tube, as opposed to the hot engine block, promote this condensation.

Generally, it's colder temps that produce the accumulations, that are a result of fuel vapors in the crankcase from the richer mixtures generated during engine warmup.

I have this extension tube on my GM 5.3L V8, and generally clean out the cap & tube at every oil change, just as a preventative measure.

 

[2K2AcuraTL]

...just keep an eye on the coolant reservoir for an drop in the level over the next little while...
J

 

[UKCatsfan]

The coolant reservoir was actually about empty and I just topped it off. Could this be related? Check out my last uoa back in Sept.

http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=3;t=002925#000000

 

[UKCatsfan]

Before you read the uoa I forgot to mention the sodium actually read 31 and not 5. Thanks for the feedback

 

[twentynine]

I posted some questions about the same thing on my Hemi several months ago.

Picture included.

http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=42;t=002773

 

[adam123]

General yellowing Foaming shouldnt be an issue this is a Normal Occurence on the Hemi 5.7 and the 4.7/3.7 But if your cooling resserve has to be constantly replenished I would serioulsly consider UOA.

 

[UKCatsfan]

I will do another UOA at the next change to check for a coolant leak. The last one I had done they mentioned the sodium was high nad to keep an eye on it. The truck only has 23,000 miles on it. Thanks for the replies...